The reason behind this new binary format was to overcome the problems in the execution of JavaScript. The web hasn’t yet utilized the full potential of asm.js and the giants like Google, Microsoft, Apple and Mozilla are teaming up to create this successor.
JavaScript creator and former Mozilla CEO Brendan Eich said that asm.js is awesome but once the engine optimize for it, the parser becomes very hot spot especially on mobile devices. The transport compression is needed for compression to save bandwidth but the decompression before parsing hurts and overloads the system. He adds that JavaScript isn’t going away anywhere in future but WebAssembly would makes things easier.
WebAssembly will provide developers a single compilation target for the web and it will be developed as a web standard to be implemented in all browsers. This will make browsers more efficient target for compilers as compared to plain JavaScript.
WebAssembly is expected to grow into portable bytecode for browsers. The early prototypes are showing some advantages like the binary representation is 20 times faster to parse (compared to equivalent asm.js).
The main teams working on WebAssembly are PNaCl team of Google and asm.js team of Mozilla, and they are working to combine their best. There is no formal standards body behind it and it is still in the early stages of development but with major browser makers backing it, WebAssembly has a bright future.
With WebAssembly’s arrival, JavaScript isn’t going anywhere. It is expected that both of these will work side by side. TechCrunch writes that some parts of application may use WebAssembly based modules while the user interface will be written mostly in JavaScript.
